Abstract

The present paper investigates nonlinear saturation of the relativistic Weibel instability by employing theory and a particle-in-cell simulation technique. It is found that the early phase of the instability is in excellent agreement with linear theory. Qualitative agreement with quasilinear prediction is also found. An analysis based on an alternative magnetic trapping saturation theory reveals that a relativistic formula leads to a substantial discrepancy between theory and simulation. However, excellent agreement is recovered in the nonrelativistic regime. The analysis of the Weibel instability beyond the quasilinear saturation stage reveals an inverse cascade process via a nonlinear decay instability involving electrostatic fluctuation.

Received 05 June 2009Accepted 17 June 2009Published online 11 August 2009

Acknowledgments:

This work was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korean government (MEST) Grant Nos. R11-2008-072-01003-0 and R01-2003-000-10402-0. P.H.Y. acknowledges NSF under Grant No. ATM0836364 to the University of Maryland and AFOSR Contract No. FA9550-07-0053 to Massachusetts Technological Laboratory.